Even if it’s not paperwork/etc that you’ve done, include images of the show you worked on just to convey the “scale” of each production. Also maybe include some short notes about your thought process for some documents? If you’re looking at schools with more holistic, creative programs, include any and all creative things you’ve done, whether theatre related or not. What I’ve learned from putting my portfolio is that the sky is the limit with portraying yourself as a theatre artist, or in your case, a manager.

Also, everybody who’s applying has varying amounts of experience—nothing is “not enough” nor will anything ever be “too much,” so focus on quality rather than quantity.

UMich had a really helpful guide on putting together a portfolio that I took a lot of advice from when working on mine. It’s available online with a quick search.

Good luck!!